Energy and Enzymes

Question 1

What is activation energy?

Answer 1

The minimum energy needed for a reaction to start.

Question 2

How does temperature affect reaction rates?

Answer 2

Higher temperatures increase molecular movement and collisions, speeding up reactions.

Question 3

What happens if reactant concentration increases?

Answer 3

More molecules collide, increasing reaction rate.

Question 4

Why do some spontaneous reactions still need an energy input?

Answer 4

To overcome activation energy and start the reaction.

Question 5

What is a catalyst?

Answer 5

A substance that increases reaction speed without being consumed.

Question 6

How do enzymes affect activation energy?

Answer 6

They lower it, making reactions occur faster.

Question 7

Why does cooling slow down reactions?

Answer 7

It decreases molecular motion, reducing collisions.

Question 8

Can enzymes change the equilibrium of a reaction?

Answer 8

No, they only speed up reaching equilibrium.

Question 9

Why is activation energy necessary even for exergonic reactions?

Answer 9

Bonds must first be broken before new ones form.

Question 10

What is an enzyme?

Answer 10

A protein that catalyzes biochemical reactions.

Question 11

What part of an enzyme binds to substrates?

Answer 11

The active site.

Question 12

What determines an enzyme’s specificity?

Answer 12

Its 3D structure and shape of the active site.

Question 13

What happens after an enzyme catalyzes a reaction?

Answer 13

It releases the product and remains unchanged.

Question 14

What is the enzyme-substrate complex?

Answer 14

The temporary binding of a substrate to an enzyme.

Question 15

Do enzymes get used up in a reaction?

Answer 15

No, they remain intact and can be reused.

Question 16

What is an example of an enzyme and its function?

Answer 16

e.g. Lipase breaks down lipids.

Question 17

What is a ribozyme?

Answer 17

A RNA molecule that functions as an enzyme.

Question 18

What happens if an enzyme’s structure is altered?

Answer 18

It may lose its ability to bind to the substrate or lose its activity.

Question 19

How do enzymes lower activation energy?

Answer 19

By orienting substrates, straining bonds, and stabilizing transition states.

Question 20

What is the “induced fit model” of enzyme function?

Answer 20

The enzyme slightly changes shape to fit the substrate.

Question 21

How do enzymes ensure reactants meet?

Answer 21

They hold substrates close together in the active site.

Question 22

What role does substrate orientation play in catalysis?

Answer 22

Proper alignment increases reaction efficiency.

Question 23

How do enzymes strain bonds?

Answer 23

They stress bonds, making them easier to break.

Question 24

What happens if an enzyme is missing its coenzyme or cofactor?

Answer 24

It may not function properly.

Question 25

Why do some enzymes require ATP?

Answer 25

ATP provides energy for catalysis.

Question 26

How do enzymes assist in phosphorylation reactions?

Answer 26

They help transfer phosphate groups, activating molecules.

Question 27

What happens if an enzyme is exposed to extreme heat?

Answer 27

It denatures, losing its function.

Question 28

What happens to the enzyme after the reaction?

Answer 28

It returns to its original state and is ready to catalyze again.

Question 29

What is competitive inhibition?

Answer 29

An inhibitor competes with the substrate for the active site.

Question 30

How does non-competitive inhibition work?

Answer 30

The inhibitor binds elsewhere, changing enzyme shape.

Question 31

What is allosteric regulation?

Answer 31

A molecule binds to a regulatory site to control enzyme function.

Question 32

Why is feedback inhibition important?

Answer 32

It prevents excess product buildup in metabolic pathways.

Question 33

How does cooperativity work in enzymes?

Answer 33

Binding of one substrate increases affinity for others.

Question 34

What is an example of feedback inhibition?

Answer 34

Isoleucine inhibiting threonine deaminase.

Question 35

How does pH affect enzyme activity?

Answer 35

Extreme pH levels can denature enzymes.

Question 36

How can enzyme activity be increased?

Answer 36

By adding more substrate or removing inhibitors.

Question 37

Why are some inhibitors irreversible?

Answer 37

They form strong covalent bonds with the enzyme.

Question 38

How do drugs target enzyme activity?

Answer 38

Many drugs act as enzyme inhibitors (e.g., antibiotics).

Question 39

How did early life evolve metabolic diversity?

Answer 39

Through enzyme adaptation to new energy sources.

Question 39

How do enzymes contribute to evolution?

Answer 39

Mutations create new metabolic pathways.

Question 40

What is an example of an enzyme that evolved for survival?

Answer 40

The bombardier beetle’s peroxidase enzyme for defense.

Question 41

How do bacteria develop antibiotic resistance?

Answer 41

Mutations in enzymes break down antibiotics.

Question 42

What role do enzymes play in digestion?

Answer 42

They help break down macromolecules into nutrients.

Question 43

How do metabolic pathways evolve?

Answer 43

Through gene duplication and mutation.

Question 44

How do extremophiles survive harsh environments?

Answer 44

They have heat-stable enzymes.

Question 45

What happens if a mutation makes an enzyme too active?

Answer 45

It can disrupt normal metabolism.

Question 46

How do enzymes influence energy production?

Answer 46

They regulate ATP production in respiration.

Question 47

Why are enzymes essential for life?

Answer 47

They speed up reactions necessary for survival.